Otitis media with effusion (OME), or serous otitis media (SOM) is a very common condition in children and, if not treated in time, may cause irrevocable setbacks in the child's development in communication skills. However, its epidemiology, etiologies, and pathogenesis are not yet clear. Recent data suggest that acute middle ear and upper respiratory infection may precede the OME. Because OME is closely related to acute otitis media (AOM), the proposed symposium and post-symposium conference are expanded to include relevant aspects of otitis media, although OME will continue to receive the main emphasis. We are planning to have a four-day symposium and a one-and-one-half-day research conference to define the state of knowledge of basic research in otitis media to determine the scientific rationale for the diagnosis, management, and prevention of this condition; and to delineate and recommend the future directions for research concerning this problem. This is the fourth such meeting, and the other three were highly successful in stimulating research interest in this clinically important problem. We also plan to publish the symposium proceedings and report of the research conference for wider dissemination of our current scientific knowledge.